Question

A piston-cylinder device contains 5 kg of saturated water liquid at 0.3 MPa. Heat is transferred at constant pressure until the temperature reaches 500 -C. (84 marks) a) What is the initial temperature of the system? b) What is the initial quality x? c) What is the initial specific enthalpy of the system? d) What is the final state? e) Show the process on a P-v diagram with respect to the saturation line. 1) What is the final specific enthalpy? Calculate the change in total volume during the process Calculate the total enthalpy increase during the process.

Answer 1

P = 0.30Pa Sinu the liquid Shate a) Initial state is Saturated T 0.30Pa 133.52'c 'Sat 561-43 Iz z 5062 state br-0. e) hi= bf at 0.30Pa kolny P2 z 0.3mpa d) Since Iz> That (0.3mpa): hisal State is superheated From Super heated tables, ba kolny Q = q Co.3mpa uz (0.3m Pa, 5060) 1. 18672 milkg 9 change in total volume = m [ua-4, ) = 5x [1. 18672 1073 5.928235 m 3486.6 0.001073 walking 0.001073 3 u total enthalpy increase - m Cha- bi]= 5*3486 -6 561.43 1462.6.5 km T=500c P 2 0.3mpa to 500c lo